Thermal Evaporation of Different Copper Nanotip Structures under High Electric Field Based on Electrodynamics – Molecular Dynamics Simulations

摘要

As the miniaturization of microelectromechanical systems (MEMS), nanoelectromechanical systems (NEMS) and molecular devices, the problem of vacuum insulation in the devices becomes more and more prominent. The nano-scale thermal effect caused by electron emission or dielectric breakdown under high electromagnetic field and local temperature, will lead to gasification and migration of the material in the device. In this work, the electrodynamics in the combination with discretized classic molecular dynamics method is used to simulate the thermal evaporation of nano-tips under high electric field. Cu nano-tips with different initial geometries and different electric fields are modeled using finite element methods to further analyze the deformation and damage mechanism of nano-tips under high electric field. Simulation results show that the length-diameter ratio of nano-tips have a significant influence on the atomic evaporation of nano-tips. The study is helpful to further explore the fundamental properties of vacuum breakdown at nano-scale.